EXHAUST GAS PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

An exhaust gas purification device for an internal combustion engine having a moisture adsorption material and a NOx adsorption material that are arranged in that order from the upstream side in an exhaust passage. Degradation, caused by moisture, in NOx adsorption ability is suitably avoided to secure sufficient NOx adsorption ability of the NOx adsorption material. The exhaust gas purification device has a main exhaust gas passage (14) in which exhaust gas from the internal combustion engine (10) flows and also has a bypass passage (20) bypassing the main exhaust gas passage (14). In the bypass passage (20) are arranged, in order from the side closer to an upstream-side connection section (20a), the moisture adsorption material (24) and the NOx adsorption material (28). At the time point when it is determined that separation of moisture from the moisture adsorption material (24) is started, a switchover valve (22) is controlled so that exhaust gas does not flow into the NOx adsorption material (28).